German patent DE 37 27 863 C1 discloses an agitator mill with a feed pipe for the grinding bodies. The grinding container comprises a rotatably driven agitator and, around the latter, a grinding space that can be filled at least partially with grinding bodies and grinding stock. A feed pipe, through which grinding bodies are fed from the exterior to a central region of the grinding container while the agitator is running, emerges into a hollow space in the agitator. An essentially radial outlet opening in the agitator is connected to the grinding space. A rapid feed of grinding bodies is thus enabled.
German patent specification DE 39 02 689 C1 discloses a device for the introduction of auxiliary grinding bodies into mills, in particular agitator mills. A housing, which is connected to a grinding container, contains a conveying space which can be connected to a grinding space in the grinding container. Auxiliary grinding bodies are fed to the conveying space through an inlet opening in the housing. A conveying element is able to move in the conveying space in order to convey auxiliary grinding bodies from the inlet opening through an elastic closure in the direction of the grinding space. The elastic closure comprises at least one slot, which extends at right angles to the conveying direction of the conveying element and is normally closed, but allows a plurality of auxiliary grinding bodies to pass through beside one another under a pressure exerted by the conveying element.
German patent specification DE 44 32 200 C1 discloses an agitator mill, wherein the latter is provided with a separate grinding stock/auxiliary grinding body separating device. The separating device comprises a rotatably driven rotor for separating the auxiliary grinding bodies from the treated grinding stock. The auxiliary grinding bodies are transported back to the agitator mill with untreated grinding stock. Together with the agitator mill and the lines connecting the latter, the separating device forms a closed system.
The agitator mill disclosed in German patent application DE 103 38 592 A1 comprises a grinding container and a rotatably driven agitator disposed in the latter. A grinding stock feed emerges into the grinding space and a grinding stock discharge emerges out of the grinding space. The grinding space is at least partially filled with auxiliary grinding bodies. The grinding stock discharge is, at one and the same time, an auxiliary grinding body extraction and separating device. It comprises a separator for auxiliary grinding bodies, which has a separating region, into the upper region whereof an extraction line dipping into the grinding stock/auxiliary grinding body mixture emerges. A sluice is integrated in the line for the auxiliary grinding body feedback.
There is known from DE 10 2009 019 501 A1 a device with which grinding bodies can be removed from an agitator ball mill. This device is a multi-part pipe, which is introduced into the grinding chamber through the grinding container floor in the vicinity of the grinding container base. As a result of a flow in the grinding container, the grinding bodies are carried out of the grinding container through openings in the pipe via a line. The pipe is disposed so as to be movable in the agitator ball mill, so that the openings are located in the region of the greatest density of grinding bodies.
Devices and methods are therefore known from the prior art, with which auxiliary grinding bodies can be introduced in the dry state into a mill. Systems are also known which make it possible to remove auxiliary grinding bodies and grinding stock jointly from a mill in order subsequently to separate the latter. A drawback with all these devices, methods and/or systems is that the mill always has to be opened for the complete removal and/or replacement of the auxiliary grinding bodies.